The present invention is directed to a component having end faces which are dereflecting or reflection-removing.
In order to achieve an optimum low reflection upon outfeed of radiation in opto-electronic components composed of waveguides, a demand has occurred for having dereflecting end faces for these waveguides. Residual reflections of less than 0.1% are often required, particularly for optical amplifiers.
The dereflecting end faces of waveguides can occur in various ways.
An article by Olsson et al entitled "Ultra-low Reflectivity 1.5 .mu.m Semiconductor Laser Preamplifiers", Electronics Letters, Vol. 24, No. 9, Apr. 28, 1988, pp. 569-570, discloses the dereflecting of end faces of a resonator of a semiconductor amplifier by utilizing dielectric layers or coatings. Narrow tolerances must be observed in the manufacture of these coatings or layers in order to achieve the required, low residual reflection. Slight residual reflection is only achieved in a narrow wavelength band.
An article by Barnsley et al entitled "Ultra-low Reflectivity Broadband 1.5 .mu.m GaInAsP Semiconductor Optical Amplifiers", Electronics Letters, Vol. 26, No. 12, Jun. 7, 1990, pp. 825-827, discloses an optical semiconductor amplifier whose waveguides extend obliquely relative to the normal of the cleavage plane of the semiconductor. A large deflection angle of approximately 20.degree.-40.degree. of the light emission relative to the normal, vis-a-vis the cleavage face of the semiconductor must be accepted in order to achieve low residual reflection. Large deflection angles are a disadvantage when coupling an optical fiber to this chip.
An article by Cha et al entitled "1.5 .mu.m Band Travelling-Wave Semiconductor Optical Amplifier with Window Facet Structure", Electronics Letters, Vol. 25, No. 3, Feb. 2, 1989, pp. 242-243 and an article by Dutta et al entitled "Fabrication and Performance Characteristic of Buried Facet Optical Amplifiers", J. Appl. Phys., Vol. 67, No. 9, May 1, 1990, pp. 3943-3947, disclose optical amplifiers having a buried waveguide end face. Dependent on the waveguide structure, a spacing of 5 .mu.m through 20 .mu.m is selected between the buried end face and the cleavage face for dereflecting the cleavage face. The effectiveness of the anti-reflection method is limited by the reflection at the end face of the waveguide in the inside of the semiconductor material.